Originally posted by hacknet i`ve just done up mine after hearing temasek`s one...

i did mine with the Fe127s instead. really good sound for the small price.

A TQWT for the F120A is going to be similar to one for the FE127E although you can tune it a little bit lower (~45Hz).
Length = 50"
driver at 25" from top
port at 48" from top
area at top = 9in^2
area at bottom = 42in^2
port diameter = 2"
port length = 3"
Start with .25lb ft^3 and stuff according to taste. You'll probably want to use a BSC with Zobel depending on your baffle width, room and personal preference. I recommend putting the driver on the slanted side. Example: